Drill.



G. A. HUMASON.

- DRILL.

APPLICATION FILED APR. 7. 191a.

1,151,104 Patented Aug. 24, 1915.

Witnesses GRANVILLE A. HUMASON, OF SHREVEPORT, LOUISIANA.

DRILL.

Specification of Letters Patent. Patented Aug. 241, 1915,

Application filed April 7, 1913. Serial N 0. 759,523.

To all whom it may concern:

Be it known that T, GRANVILLE A. HUMA- SON, a citizen of the United States, residing at Shreveport, in the parish of Caddo and State of Louisiana, have invented a new and useful Drill, of which the following is a specification.

This invention relates to rock drilling bits and is more particularly designed as an improvement upon the structure disclosed in an application filed by me on February 10, 1913, said application bearing Serial No. 747,461. g

In bits of the type set forth, it has been customary to use-side cutting disks the lower or active portions of which extend outwardly such distances that the bore produced by the drill will be of slightly greater diametergthan the greatest diameter of the head of the drill. These disks have been arranged in planes converging upwardly. It

has been found in actual practice that where disks have been thus disposed for the purpose mentioned, the outer edges of the peripheries thereof soon wear away thus reducing the diameter of the cut made by the disks when the head is rotated and ultimately the disks wear to such an extent that it becomes impossible for the head of the drill to follow them into the bore. 'lhus the bore becomes choked and it is necessary to withdraw the drill and substitute new cuttin disks for those previously used. a

ne of the objects of the present invention is to provide side cutting disks which do not present sharp angles to the'wall of the bore and which will not quickly wear away.

With the foregoing and other objects in view which will appear as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention herein disclosed, can be made within the scope of what is claimed, without, departing from the spirit of the invention.

In the accompanying drawings the preferred form of the invention has been shown. In said drawings, Figure 1 is a view partly in section and partly in elevation'of a drill embodying the present improvements. Fig. 2 is a section on line AB Fig. 1. Fig. 3 is an elevation of a 'portion of a drill having a slightly modified form of cutter.

Referring to the figures by characters of reference 1 designates a drill head which gradually enlarges toward its lower or active end, said end being formed with a recess 2 extending partly across the same and in which are arranged suitable cutters such as indicated at 3. These cutters do not constitute any part of the present invention and it is not, therefore, deemed necessary to describe or illustrate them in detail. The upper threaded end of the head 1 is engaged by the threaded end of a tubular rod 4: into which water used in flushing the here is adapted to be directed in any suitable manner. Extending upwardly into the active end of the head 1 at opposite sides of recess 2 are sockets or channels 5 which converge upwardly. Extending across the lower por- 1 tion of each of these channels is a bearing pin 6 similar to that shown in my application hereinbefore referred to, there being a bushing 7 upon the pin. A longitudinal bore 8'is formed in the pin'and is closed at its outer end by a screw plug 9 or the like, this bore communicating with an oil duct 10 formed in the head and extending up to and adapted to receive a lubricant from a central bore 11 formed in the head. lubricant holding tube 12 extends upwardly from the upper end of the head 1 and opens intothe bore 11', the lower end of this tube being closed by a screw plug 13 or the like in the periphery of which are formed grooves or channels 14 constituting outlets whereby lubricant contained within the tube 12 can flow downwardly into the bore 11. Tube 12 is preferably connected by a coupling 15, to a larger lubricant containing tube 16, the coupling 15 thus forming a shoulder tending to retard downward flow of the lubricant. The upper end of tube 16 is located below the upper end of the tube 4 so that water contained in said tube 4 will be free to flow into the tube 16 andthusbear downwardly onto the lubricant contained within said tube 16. P

Water ducts 17 are formed in the head 1 andextend to the upper ends of the recesses or channels 5 whereby water contained within the tubular rod 4 will be free to flow downwardly through these ducts and into therein through which the water and the material carried thereby can flow freely.

Mounted on the bushings 7 are side cutting disks of novel form. In the structure shown in Fig. 1 each cutting disk 19, is frusto-conical so that, when it is supported in an inclined plane as shown, the lowermost portion lies in a plane parallel with the bottom of the head 1, as shown in Fig. 1. The lower portion of each disk 19 projects beyond a vertical line extending along the side of the head whereby the bore is enlarged so as to be greater than the greatest diameter of the head 1. It is-known to be old to' use cutters arranged in this manner for producing a bore of greater diameter than the .diameter of the head carrying the cutters but, as. hereinbefore stated, cutters of this character have presented sharp. angles along the outer edges of their peripheries, these .angles soon wearing off by reason of their contact with the wall of the bore. As a result, the bore has gradually diminished in diameter as the cutting disks have worn away. To overcome this objectionable feature, each of the cutting disks 19 has the outer edge of its periphery cut away 01' beveled, as shown at 20, the bevel being such that the lowermost portion thereof is extended along a vertical line or along a line parallel with the longitudinal axis of the head 1. Thus it will be seen that during the cutting operation, the active portion of the face 20 will be along a line parallel with the direction of movement of the cutter and the wear upon the disk will be reduced to the minimum and, consequently, the life of the cutting disk will be greatly prolonged.

Instead of utilizing a frusto-conical cutting disk such as shown in Fig. 1, a substantially cylindrical cutting disk may be employed. One of these disks has been illustrated at. 21 in Fig. 3, the outer edge of the periphery of this disk being beveled as at 22 similarly to the structure shown in Fig.

1 and'for the same purpose.

It is t be understood that the drill is to be rotate slowly as itis moved upwardly and downwardly and each time the drill is dropped so as to-cut the body thereunder, the water contained intube 4 above tube 16 will pack downwardly upon the lubricant contained within the tubes 12 and 16. This lubricant is preferably in the form of a paste and, as it is subjected to the pressure of the water, the lubricant will be forced through-the channels 14 and into the bore 11 and thence into the ducts 10 where the lubricant will be heated, the heat being obtained by the frictional engagement of the drill with the rock being cut. Thus the' groove 23 such as described, there is no surface presented at the inner side of the cutting disk which would tend to pack downwardly on the surface being cut, as would be the case should a flat inclined face extend from the upper end of the cutting edge of the tooth on the diskand inwardly to the center of the inner side of the disk.

What is claimed is 1. A drill bit including a body having inwardly converging sockets, and a cutting disk mounted for rotation within each socket, said disks being revoluble in planes converging inwardly, each disk having atoothed periphery, the outer side of the peripheral portion of each disk being eled and the inner side of the peripheral portion of each disk being cut away, whereby the inner and outer ends of each tooth when in active aor cutting position are disposed along lines substantially parallel with the longitudinal axis of the bit.

2. A drill bit including a head, a cutting disk mounted for rotation therein within a plane-obliquely disposed relative to the head, said disk having peripheral cutting teeth, the inner and outer end of each tooth, when the tooth is in active or cutting posibevtion, being substantially parallel with the longitudinal axis'of the head. I

3. .A drill bit including a head having in-.

wardly converging sockets in the active end thereof, a bearing pin extending toward each socket, the inner end of each-bearing pin being reduced and screw threaded for engagement with the inner wall of the socket, and the outer end of each bearing pin being shouldered, and a cutting disk mounted for rotation on each pin, each disk having peripheral teeth, the ends of each tooth, when in active or cutting position, being parallel with the longitudinal axis of the head.

In testimony that I claim the foregoing as my own, I havehereto afiixed my signature in the presence of two witnesses.

GRANVILLE A. 'HUMASON.

Witnesses:

SELINA WILISON,

JOHN L. KIMBAL. 

